模拟淋溶条件下沼液对菜田土壤磷素淋洗及其形态的影响

Effects of Application of Biogas Slurry on the Form and Mobility of Soil Phosphorus in Vegetable Greenhouse Field

以不同磷水平菜田土壤为研究对象,通过土柱淋溶模拟试验,探讨施用沼液对土壤磷素形态及其移动性的影响。结果表明:与单施去离子水的对照相比,施用沼液通过减少淋洗溶液体积降低淋洗液中总磷含量722.3μg·柱^(-1),中、高磷土壤淋洗液总无机磷(TIP)分别减少507.2μg·柱^(-1)和1 319μg·柱^(-1)。低、中磷土壤淋洗液中水溶性无机磷(DIP)减少158.1μg·柱^(-1)和474.3μg·柱^(-1)。在低磷土壤中,施用沼液对剖面土壤全磷、有机磷和速效磷含量影响显著,上层(0~7 cm)土壤增加的比例分别为34.8%、37.7%和148%,土壤p H值显著降低0.39个单位,下层(7~14 cm)土壤增加的比例分别为18.5%、29.3%和32.9%,土壤p H值显著降低0.28个单位。在中磷土壤中,施用沼液对上层土壤全磷含量影响未达到显著水平,速效磷增加比例20.1%,下层土壤p H值降低0.33个单位。在高磷土壤中,施用沼液对剖面土壤全磷、有机磷和速效磷含量影响未达到显著水平,下层土壤p H值降低0.34个单位。因此,施用沼液降低土壤磷素淋洗,增加低磷土壤磷素有效性含量,但对中磷和高磷水平土壤的磷素影响未达到显著水平。

A packed soil column experiment was conducted to investigate the effects of biogas slurry on phosphorus（P）form and mobility in a vegetable greenhouse soil with different P fertility levels. The results showed that application of biogas slurry all significantly reduced leachate volume and total phosphorus leaching in the experimental soil with different fertility levels. Compared with control treatments, the application of biogas slurry decreased total phosphorus content in leachate by 722.3 μg·column^-1through reducing leachate volume. Total inorganic phosphorus（TIP）decreased by 507.2 μg·column^-1and 1 319 μg·column^-1in the moderate-P-fertility and high-P-fertility soil, respectively.Dissolved inorganic phosphorus（DIP）was decreased by 158.1 μg·column^-1and 474.3 μg·column^-1in the low-P-fertility and moderate-Pfertility soil, respectively. In low-P-fertility soil, biogas slurry application significantly increased soil total P, Olsen-P and organic P in 0~7cm soil depth by a proportion of 34.8%, 37.7% and 148%, respectively. It also reduced soil p H by 0.39 units. In 7~14 cm soil depth, biogas slurry application significantly increased soil total P, Olsen-P and organic P by a proportion of 18.5%, 29.3% and 32.9%, respectively. Soilp H was also decreased by 0.28 units. In moderate-P-fertility soil, application of biogas slurry had no significantly influence on soil total P, but increased soil Olsen-P by 20.1% in 0~7 cm soil depth compared with control treatment. In 7~14 cm soil depth, application of biogas slurry reduced soil p H by 0.33 units. In high-P-fertility soil, application of biogas slurry had no significantly influence on soil total P, Olsen-P and organic P in 0~7 cm soil depth compared with control treatment. In 7~14 cm soil depth, application of biogas slurry reduced soil p H by 0.34 units. In conclusion, application of biogas slurry significantly increased different forms of phosphorus contents in low-P-fertility soil, however,there was no significantly difference on the P forms in moderate-P-fertility soil and high-P-fertility soil.